This invention relates to a scroll type positive fluid displacement apparatus for compressing, expanding or pumping fluids.
The principles of operation of a scroll apparatus will be explained with reference to FIG. 1, which shows a stationary involute or spiral-shaped scroll 1 and an orbiting scroll 2 of like shape but displaced and rotated 180.degree.. The orbiting scroll 2 performs orbital motion about a point without rotation. Thus, a side of the orbiting scroll moves so as to always remain in a parallel position. Compression pockets 3 and 5 are formed in the space between the stationary and orbiting scroll members whose volumes are decreased (assuming compressing operation) during orbiting about a central point O as shown in the sequence of FIGS. 1(a)-1(d) until they merge into a single, similarly, shrinking central outlet pocket 8'. At the same time, new inlet pockets are formed as shown in FIG. 1(c) at 3, 5, which progressively shrink or are compressed.
The U.S. Pat. Nos. 3,884,599 and 4,065,279 disclose scroll type positive fluid displacement apparatus to ensure axial and radial sealing of the scroll assembly.
The U.S. Pat. No. 1,906,142 shows an exteriorly cylindrical boss for permitting the scrolls to move a little in a radial direction on a crank pin.